End of life: 10/31/2031, End of support: 10/9/2028, Latest version: 3.15.0

Potential DoS via quadratic complexity in unicodedata.normalize()

The "profiling.sampling" module (Python 3.15+) and "asyncio introspection capabilities" (3.14+, "python -m asyncio ps" and "python -m asyncio pstree") features could be used to read and write addresses in a privileged process if that process connected to a malicious or "infected" Python process via the remote debugging feature. This vulnerability requires persistently and repeatedly connecting to the process to be exploited, even after the connecting process crashes with high likelihood due to ASLR.

Out-of-memory when loading Plist

End of life: 10/31/2030, End of support: 10/1/2027, Latest version: 3.14.8

Summary

In the fallback extraction path for source distributions, pip used Python’s tarfile module without verifying that symbolic/hard link targets resolve inside the intended extraction directory. A malicious sdist can include links that escape the target directory and overwrite arbitrary files on the invoking host during pip install.

Impact

Successful exploitation enables arbitrary file overwrite outside the build/extraction directory on the machine running pip. This can be leveraged to tamper with configuration or startup files and may lead to further code execution depending on the environment, but the direct, guaranteed impact is integrity compromise on the vulnerable system.

Conditions

The issue is triggered when installing an attacker-controlled sdist (e.g., from an index or URL) and the fallback extraction code path is used. No special privileges are required beyond running pip install; active user action is necessary.

Remediation

The fix, while available as a patch that can be manually applied, has not yet been put into a numbered version but is planned for 25.3. Using a Python interpreter that implements the safe-extraction behavior described by PEP 706 provides additional defense in depth for other tarfile issues but is not a substitute for upgrading pip for this specific flaw.

Last updated 24 March 2025

End of life: 10/31/2027, End of support: 4/1/2024, Latest version: 3.11.17

End of life: 10/31/2027, End of support: 4/1/2024, Latest version: 3.11.17

End of life: 10/31/2029, End of support: 10/1/2026, Latest version: 3.13.16

End of life: 10/31/2029, End of support: 10/1/2026, Latest version: 3.13.16

It was discovered that Python incorrectly handled certain inputs. An attacker could possibly use this issue to execute arbitrary code. This issue only affected Ubuntu 14.04 LTS and Ubuntu 18.04 LTS. (CVE-2015-20107) It was discovered that Python incorrectly used regular expressions vulnerable to catastrophic backtracking. A remote attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 14.04 LTS. (CVE-2018-1060, CVE-2018-1061) It was discovered that Python failed to initialize Expat’s hash salt. A remote attacker could possibly use this issue to cause hash collisions, leading to a denial of service. This issue only affected Ubuntu 14.04 LTS. (CVE-2018-14647) It was discovered that Python incorrectly handled certain pickle files. An attacker could possibly use this issue to consume memory, leading to a denial of service. This issue only affected Ubuntu 14.04 LTS. (CVE-2018-20406) It was discovered that Python incorrectly validated the domain when handling cookies. An attacker could possibly trick Python into sending cookies to the wrong domain. This issue only affected Ubuntu 14.04 LTS. (CVE-2018-20852) Jonathan Birch and Panayiotis Panayiotou discovered that Python incorrectly handled Unicode encoding during NFKC normalization. An attacker could possibly use this issue to obtain sensitive information. This issue only affected Ubuntu 14.04 LTS. (CVE-2019-9636, CVE-2019-10160) It was discovered that Python incorrectly parsed certain email addresses. A remote attacker could possibly use this issue to trick Python applications into accepting email addresses that should be denied. This issue only affected Ubuntu 14.04 LTS. (CVE-2019-16056) It was discovered that the Python documentation XML-RPC server incorrectly handled certain fields. A remote attacker could use this issue to execute a cross-site scripting (XSS) attack. This issue only affected Ubuntu 14.04 LTS. (CVE-2019-16935) It was discovered that Python documentation had a misleading information. A security issue could be possibly caused by wrong assumptions of this information. This issue only affected Ubuntu 14.04 LTS and Ubuntu 18.04 LTS. (CVE-2019-17514) It was discovered that Python incorrectly stripped certain characters from requests. A remote attacker could use this issue to perform CRLF injection. This issue only affected Ubuntu 14.04 LTS and Ubuntu 18.04 LTS. (CVE-2019-18348) It was discovered that Python incorrectly handled certain TAR archives. An attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 14.04 LTS and Ubuntu 18.04 LTS. (CVE-2019-20907) Colin Read and Nicolas Edet discovered that Python incorrectly handled parsing certain X509 certificates. An attacker could possibly use this issue to cause Python to crash, resulting in a denial of service. This issue only affected Ubuntu 14.04 LTS. (CVE-2019-5010) It was discovered that incorrectly handled certain ZIP files. An attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 14.04 LTS. (CVE-2019-9674) It was discovered that Python incorrectly handled certain urls. A remote attacker could possibly use this issue to perform CRLF injection attacks. This issue only affected Ubuntu 14.04 LTS. (CVE-2019-9740, CVE-2019-9947) Sihoon Lee discovered that Python incorrectly handled the localfile: scheme. A remote attacker could possibly use this issue to bypass blocklist meschanisms. This issue only affected Ubuntu 14.04 LTS. (CVE-2019-9948) It was discovered that Python incorrectly handled certain IP values. An attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 14.04 LTS and Ubuntu 18.04 LTS. (CVE-2020-14422) It was discovered that Python incorrectly handled certain character sequences. A remote attacker could possibly use this issue to perform CRLF injection. This issue only affected Ubuntu 14.04 LTS and Ubuntu 18.04 LTS. (CVE-2020-26116) It was discovered that Python incorrectly handled certain inputs. An attacker could possibly use this issue to execute arbitrary code or cause a denial of service. This issue only affected Ubuntu 14.04 LTS. (CVE-2020-27619, CVE-2021-3177) It was discovered that Python incorrectly handled certain HTTP requests. An attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 14.04 LTS. (CVE-2020-8492) It was discovered that the Python stdlib ipaddress API incorrectly handled octal strings. A remote attacker could possibly use this issue to perform a wide variety of attacks, including bypassing certain access restrictions. This issue only affected Ubuntu 18.04 LTS. (CVE-2021-29921) David Schwörer discovered that Python incorrectly handled certain inputs. An attacker could possibly use this issue to expose sensitive information. This issue only affected Ubuntu 18.04 LTS. (CVE-2021-3426) It was discovered that Python incorrectly handled certain RFCs. An attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 14.04 LTS. (CVE-2021-3733) It was discovered that Python incorrectly handled certain server responses. An attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 14.04 LTS. (CVE-2021-3737) It was discovered that Python incorrectly handled certain FTP requests. An attacker could possibly use this issue to expose sensitive information. This issue only affected Ubuntu 14.04 LTS and Ubuntu 18.04 LTS. (CVE-2021-4189) It was discovered that Python incorrectly handled certain inputs. An attacker could possibly use this issue to execute arbitrary code. This issue only affected Ubuntu 14.04 LTS and Ubuntu 18.04 LTS. (CVE-2022-0391) Devin Jeanpierre discovered that Python incorrectly handled sockets when the multiprocessing module was being used. A local attacker could possibly use this issue to execute arbitrary code and escalate privileges. This issue only affected Ubuntu 22.04 LTS. (CVE-2022-42919) It was discovered that Python incorrectly handled certain inputs. If a user or an automated system were tricked into running a specially crafted input, a remote attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 14.04 LTS, Ubuntu 18.04 LTS and Ubuntu 22.04 LTS. (CVE-2022-45061, CVE-2023-24329) It was discovered that Python incorrectly handled certain scripts. An attacker could possibly use this issue to execute arbitrary code or cause a crash. This issue only affected Ubuntu 14.04 LTS and Ubuntu 18.04 LTS. (CVE-2022-48560) It was discovered that Python incorrectly handled certain plist files. If a user or an automated system were tricked into processing a specially crafted plist file, an attacker could possibly use this issue to consume resources, resulting in a denial of service. This issue only affected Ubuntu 14.04 LTS and Ubuntu 18.04 LTS. (CVE-2022-48564) It was discovered that Python did not properly handle XML entity declarations in plist files. An attacker could possibly use this vulnerability to perform an XML External Entity (XXE) injection, resulting in a denial of service or information disclosure. This issue only affected Ubuntu 14.04 LTS and Ubuntu 18.04 LTS. (CVE-2022-48565) It was discovered that Python did not properly provide constant-time processing for a crypto operation. An attacker could possibly use this issue to perform a timing attack and recover sensitive information. This issue only affected Ubuntu 14.04 LTS and Ubuntu 18.04 LTS. (CVE-2022-48566) It was discovered that Python instances of ssl.SSLSocket were vulnerable to a bypass of the TLS handshake. An attacker could possibly use this issue to cause applications to treat unauthenticated received data before TLS handshake as authenticated data after TLS handshake. This issue only affected Ubuntu 14.04 LTS, Ubuntu 18.04 LTS, Ubuntu 20.04 LTS and Ubuntu 22.04 LTS. (CVE-2023-40217) It was discovered that Python incorrectly handled null bytes when normalizing pathnames. An attacker could possibly use this issue to bypass certain filename checks. This issue only affected Ubuntu 22.04 LTS. (CVE-2023-41105) It was discovered that Python incorrectly handled privilege with certain parameters. An attacker could possibly use this issue to maintain the original processes' groups before starting the new process. This issue only affected Ubuntu 23.10. (CVE-2023-6507) It was discovered that Python incorrectly handled symlinks in temp files. An attacker could possibly use this issue to modify the permissions of files. This issue only affected Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS and Ubuntu 23.10. (CVE-2023-6597) It was discovered that Python incorrectly handled certain crafted zip files. An attacker could possibly use this issue to crash the program, resulting in a denial of service. (CVE-2024-0450)

End of life: 10/31/2028, End of support: 4/2/2025, Latest version: 3.12.15

End of life: 10/31/2028, End of support: 4/2/2025, Latest version: 3.12.15

It was discovered that Python incorrectly handled certain scripts. An attacker could possibly use this issue to execute arbitrary code or cause a crash.

Yebo Cao discovered that Python incorrectly handled certain URLs. An attacker could use this issue to bypass blockinglisting methods. This issue was first addressed in USN-5960-1, but was incomplete. Here we address an additional fix to that issue. (CVE-2023-24329)

Yebo Cao discovered that Python incorrectly handled certain URLs. An attacker could possibly use this issue to bypass blocklisting methods by supplying a URL that starts with blank characters.

It was discovered that Python incorrectly handled certain inputs. If a user or an automated system were tricked into opening a specially crafted input file, a remote attacker could possibly use this issue to execute arbitrary code. (CVE-2015-20107) Hamza Avvan discovered that Python incorrectly handled certain inputs. If a user or an automated system were tricked into running a specially crafted input, a remote attacker could possibly use this issue to execute arbitrary code. (CVE-2021-28861) It was discovered that Python incorrectly handled certain inputs. If a user or an automated system were tricked into running a specially crafted input, a remote attacker could possibly use this issue to execute arbitrary code. (CVE-2022-37454, CVE-2022-42919) It was discovered that Python incorrectly handled certain inputs. If a user or an automated system were tricked into running a specially crafted input, a remote attacker could possibly use this issue to cause a denial of service. (CVE-2022-45061, CVE-2023-24329)

It was discovered that the Python urllib http client could enter into an infinite loop when incorrectly handling certain server responses (100 Continue response). Specially crafted traffic from a malicious HTTP server could cause a denial of service (Dos) condition for a client.

End of life: 10/1/2026, End of support: 4/5/2023, Latest version: 3.10.22

End of life: 10/1/2026, End of support: 4/5/2023, Latest version: 3.10.22

It was discovered that Python incorrectly handled certain RFCs. An attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 16.04 ESM. (CVE-2021-3733) It was discovered that Python incorrectly handled certain server responses. An attacker could possibly use this issue to cause a denial of service. (CVE-2021-3737)

USN-4754-1 fixed vulnerabilities in Python. This update provides the corresponding updates for Ubuntu 18.04 and Ubuntu 20.04. In the case of Python 2.7 for 20.04, these additional fixes are included: It was dicovered that Python allowed remote attackers to cause a denial of service (resource consumption) via a ZIP bomb. (CVE-2019-9674) It was discovered that Python had potentially misleading information about whether sorting occurs. This fix updates the documentation about it. (CVE-2019-17514) It was discovered that Python incorrectly handled certain TAR archives. An attacker could possibly use this issue to cause a denial of service. (CVE-2019-20907) It was discovered that Python allowed an HTTP server to conduct Regular Expression Denial of Service (ReDoS) attacks against a client because of urllib.request.AbstractBasicAuthHandler catastrophic backtracking. (CVE-2020-8492) It was discovered that Python allowed CRLF injection if the attacker controls the HTTP request method, as demonstrated by inserting CR and LF control characters in the first argument of HTTPConnection.request. (CVE-2020-26116) Original advisory details: It was discovered that Python incorrectly handled certain inputs. An attacker could possibly use this issue to execute arbitrary code or cause a denial of service. (CVE-2020-27619, CVE-2021-3177)

It was discovered that Python incorrectly handled certain character sequences. A remote attacker could possibly use this issue to perform CRLF injection.

It was discovered that Python documentation had a misleading information. A security issue could be possibly caused by wrong assumptions of this information. This issue only affected Ubuntu 12.04 ESM, Ubuntu 14.04 ESM, Ubuntu 16.04 LTS and Ubuntu 18.04 LTS. (CVE-2019-17514) It was discovered that Python incorrectly handled certain TAR archives. An attacker could possibly use this issue to cause a denial of service. (CVE-2019-20907) It was discovered that incorrectly handled certain ZIP files. An attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 12.04 ESM, Ubuntu 14.04 ESM, Ubuntu 16.04 LTS and Ubuntu 18.04 LTS. (CVE-2019-9674) It was discovered that Python incorrectly handled certain IP values. An attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 14.04 ESM, Ubuntu 16.04 LTS, Ubuntu 18.04 LTS and Ubuntu 20.04 LTS. (CVE-2020-14422)

USN-4333-1 fixed vulnerabilities in Python. This update provides the corresponding update for Ubuntu 20.04 LTS. Original advisory details: It was discovered that Python incorrectly stripped certain characters from requests. A remote attacker could use this issue to perform CRLF injection. (CVE-2019-18348) It was discovered that Python incorrectly handled certain HTTP requests. An attacker could possibly use this issue to cause a denial of service. (CVE-2020-8492)

It was discovered that Python incorrectly stripped certain characters from requests. A remote attacker could use this issue to perform CRLF injection. (CVE-2019-18348) It was discovered that Python incorrectly handled certain HTTP requests. An attacker could possibly use this issue to cause a denial of service. (CVE-2020-8492)

USN-4151-1 fixed several vulnerabilities in Python. This update provides the corresponding update for Ubuntu 12.04 ESM and Ubuntu 14.04 ESM. Original advisory details: It was discovered that Python incorrectly parsed certain email addresses. A remote attacker could possibly use this issue to trick Python applications into accepting email addresses that should be denied. (CVE-2019-16056) It was discovered that the Python documentation XML-RPC server incorrectly handled certain fields. A remote attacker could use this issue to execute a cross-site scripting (XSS) attack. (CVE-2019-16935)

It was discovered that Python incorrectly parsed certain email addresses. A remote attacker could possibly use this issue to trick Python applications into accepting email addresses that should be denied. (CVE-2019-16056) It was discovered that the Python documentation XML-RPC server incorrectly handled certain fields. A remote attacker could use this issue to execute a cross-site scripting (XSS) attack. (CVE-2019-16935)

USN-4127-1 fixed several vulnerabilities in Python. This update provides the corresponding update for Ubuntu 12.04 ESM and Ubuntu 14.04 ESM. Original advisory details: It was discovered that Python incorrectly handled certain pickle files. An attacker could possibly use this issue to consume memory, leading to a denial of service. This issue only affected Ubuntu 14.04 ESM. (CVE-2018-20406) It was discovered that Python incorrectly validated the domain when handling cookies. An attacker could possibly trick Python into sending cookies to the wrong domain. (CVE-2018-20852) Jonathan Birch and Panayiotis Panayiotou discovered that Python incorrectly handled Unicode encoding during NFKC normalization. An attacker could possibly use this issue to obtain sensitive information. (CVE-2019-9636, CVE-2019-10160) Colin Read and Nicolas Edet discovered that Python incorrectly handled parsing certain X509 certificates. An attacker could possibly use this issue to cause Python to crash, resulting in a denial of service. This issue only affected Ubuntu 14.04 ESM. (CVE-2019-5010) It was discovered that Python incorrectly handled certain urls. A remote attacker could possibly use this issue to perform CRLF injection attacks. (CVE-2019-9740, CVE-2019-9947) Sihoon Lee discovered that Python incorrectly handled the localfile: scheme. A remote attacker could possibly use this issue to bypass blocklist meschanisms. (CVE-2019-9948)